Change of the Electronic Conductivity of CNTs and Graphene Sheets Caused by a Three-dimensional Strain Field

Since the electronic structure of deformed carbon nanotubes (CNTs) varies widely depending on their chirality and deformation mode, CNTs have the potential to be high-quality strain sensors. The authors revealed the possibility of the high sensitive strain sensor using popular resin in which multi-walled CNTs (MWNTs) are dispersed uniformly. However, there was large fluctuation of the measured change rate among test samples. Thus, it is very important to clarify the mechanism of the resistance change of a deformed CNT. In this study, in order to clarify the relationship between the deformation of a CNT and its electronic conductivity, density functional theory (DFT), tight-binding (TB) approach and molecular dynamics (MD) simulation were applied. The analysis result indicates that the hybridization is the dominant factor which changes the electronic properties of GNRs and CNTs. It is concluded, therefore, that it is possible to predict the change of the local electronic state of a deformed CNT by using the analysis result of GNRs.